Insurers say costs aren't their only concern. Evidence is lacking that the precision medicine approach will work consistently, they argue.
America's Health Insurance Plans, an industry group, said genetic sequencing remains unproven.
Cathryn Donaldson, the group's spokeswoman, described recent scientific advances as "remarkable and noteworthy." But she said insurers "need a more definitive answer" about whether the tests help the average patient live longer.
The South Dakota State Employee Health Plan — which runs Kilmer's insurance plan — said it bases its coverage decisions on science and reviews "published, randomized data about the safety and efficacy of the requested drugs."
Although genetic testing has become the standard of care for melanoma and a common type of lung cancer, no one knows if genomic sequencing will extend the lives of people with other types of cancer, said Dr. Carolyn Presley, an assistant professor at the Ohio State University Comprehensive Cancer Center.